Traction cylinder

ABSTRACT

The fluid-actuated traction cylinder according to the invention is of particular utility notably in the interior of deformable collapsible chambers. It comprises a substantially cylindrical tubular supple deformable enclosure closed at both ends and the lateral surface of which comprises elements articulated with one another along the generatrices of the surface of said cylindrical enclosure, supple band means, mounted on said cylindrical surface and having its ends attached to said members, and means for inflating or deflating said enclosure by means of a pressurized fluid.

United States Patent [72] Inventor Paul J. Zuppiger Athenaz, Switzerland[21] Appl. No. 801,669

[22] Filed Feb. 24,1969

[45] Patented Mar. 16, 1971 [73] Assignee MacGregor-Comarain Paris,France [54] TRACTION CYLINDER 9 Claims, Drawing Figs.

[52] U.S.Cl 254/150, 29/113,242/47.01

[51] lnt.Cl B66d l/ 254/150,

[] Field of Search [5 6] References Cited FOREIGN PATENTS 434,63710/1967 Switzerland Primary Examiner-Harvey C. Hornsby Attorneys-Kenyon& Kenyon and Reilly, Carr & Chapin ABSTRACT: The fluid-actuated tractioncylinder according to the invention is of particular utility notably inthe interior of deformable collapsible chambers. It comprises asubstantially cylindrical tubular supple deformable enclosure closed atboth ends and the lateral surface of which comprises elementsarticulated with one another along the generatrices of the surface ofsaid cylindrical enclosure, supple band means,

' mounted on said cylindrical surface and having its ends attached tosaid members, and means for inflating or deflating said enclosure bymeans of a pressurized fluid.

PATENTED m 1 s m /NVE'A/TOF? PAUL J. ZU P/GEP BY ATTOPNEYS TRACTHQNCYLKNDER The present invention has for its object a fluid-actuatedtraction cylinder suitable for use, notably, in the interior ofyieldable or deformable chambers subjected to external loads capable ofcollapsing the same, the said traction cylinder being designed so thatits elements will not injure the wall of the said chambers.

This traction cylinder may, for instance, be advantageously used forproducing contractions or shrinkings of the various enclosures providedin handling devices of the type described in the US. Pat. applicationSer. No. 766,168 filed on Oct. 9, i968 and entitled l-landling device".

The traction cylinder according to the invention is remarkable notablyin that it comprises:

a substantially cylindrical tubular deformable supple enclosure withclosed ends, the lateral surface of which comprises elements articulatedwith one another along the generatrices of the said cylindrical surface;

at least one supple band, strap or the like rolled round or fixed to thesaid cylindrical surface and the ends of which are fixed to the elementswhich it is desired to move nearer to one another;

means for inflating or deflating the said enclosure by means ofpressurized fluid.

According to another characteristic feature of the invention, at leastsome of the said articulated elements of the said supple cylindricalenclosure are inextensible.

Advantageously there is provided such an inextensible elemer t to whichthe said band or the like is fixed and which has a section substantiallyin the shape of an arc of a circle, the curvature of which variesaccording to the inflating of the traction cylinder and which in thedeflated state forms an almost closed circle in which are located theother accordionpleated elements of the enclosure.

The invention will be understood more clearly from the followingdescription of some forms of embodiment given solely by way of examplewith reference to the following drawings in which:

FIG. 1 is a diagrammatic perspective view of a traction cylinder atrest, according to the invention;

FIGS. 2 and 3 are diagrammatic cross-sectional views of the tractioncylinder shown in FIG. 1, illustrating two stages of operation;

H6. 4 is a perspective view, with a part broken away, of an element ofthe traction cylinder according to a modified form of embodiment;

FIG. 5 shows a modified fonn of embodiment of a traction bandrepresented in FIG. 1.

According to the form of embodiment illustrated in FIGS. 1 to 3, atraction cylinder is formed of a substantially cylindrical tubularsupple deformable enclosure 1 around which are rolled three suppleinextensible straps 2a, 2b and 2c and which is adapted to be filled withpressurized fluid, for instance compressed air, supplied from a source(not shown) through conduits 3a, 3b extending from each end of theenclosure.

T he straps 2a, 2b and 2c are designed to be attached, at one end, to astationary bearing point materialized in the drawing by a fitting 5embedded in a wall element 6, the other end being attached to a point 7of the object on which the traction cylinder according to the inventionis to exert a traction force.

The traps may be replaced by any other adequate flexible inextensibleties such as strings, cords, cables, chains, strips, laces, etc...

Part of the periphery of the enclosure 1 is-constituted by an elementforming a thin supple inextensible wall 8 in the shape of an arc of acircle, whereas the remaining part is constituted by an advantageouslyinextensible wall 9 capable of becoming accordion-pleated and vsealinglyconnecting the longitudinal edges of the thin wall 8.

The straps 2a, 2b and 2c may be fixed to the thin wall S by anyappropriate means, for instance by sticking or riveting as shown at 16,or may simply be made to adhere to the enclosure without beingmaterially secured to the latter. Altemadispensed with, except on theportions of the thin wall adjacent to the free portions of the strap.

Advantageously, elastic stiffening ribs 10 may be provided on the wall 9along folding generating lines; the said ribs may be secured, forinstance stuck, to the wall 9, or, alternatively, made integral with thelatter; in the latter case they may consist of extra-thicknessescorresponding to the said wall.

The said ribs are sufficiently rigid to be able, owing to their ownelasticity, to move the various elements 9a, 9b, 9c... of the foldablewall 9 back to their folded position when the enclosure 1 is deflated.

The substantially cylindrical enclosure 1 is connected at both ends bytruncated portions la and 1b to fluid intake and escape conduits 3a, 3b.

The traction cylinder operates as follows:

at rest, that is to say when the enclosure 1 is not inflated, the thinwall 8 is in a cylindrically subsided position and the wall 9 is foldedin the opening thereof (FIG. 2).

When pressurized air is blown into the enclosure 1, the latter inflatesand the wall 9 of the enclosure (FIG. 3) unfolds in accordion-pleatedshape. l

During this motion, the strips 2 slide by their free portio over theunfolding wall 9, whereby point 7 moves nearer to point 5 over adistance d corresponding to the variation of the perimeter of theenclosure 1 between the inflated position (FIG. 3) and the deflatedposition (FIG. 2).

During this displacement of point 7, the effort T put forth by thetraction cylinder is equal to;

T=ps 0.1.

where p air pressure D= diameter of the enclosure 1 effective length ofthe enclosure [3 efficiency of the traction cylinder depending on theelasticity of the enclosure, friction between the straps and the wall,etc...

It is therefore seen that the traction cylinder is capable of exertingon the straps an effort which increases gradually as the diameter D ofthe enclosure augments, the pressure .1; remaining constant.

In addition, such a traction cylinder is characterized in that itstravel exceeds its dimensions. Furthermore, the said travel may beincreased, for instance doubled or trebled, by giving the straps morethan one turn, for instance two or three, round the enclosure. in thelatter case, the coefficient of friction between the strap and theenclosure must be low.

Since the traction cylinder is made of supple material, it can easily beplaced in proximity to very light and delicate pieces of material andeven come into contact with the said material without damaging the same.

The return of the traction cylinder to its position of rest (FIGS. l and2) may be obtained in various manners.

For instance, it can take place solely as a result of adequate rigidityof the elements 9a, 9b, 9c... of the wall 9 and the associatedstiffening elements 10;

it can result from contraction of the thin wall 8 according to an arc ofa circle of smaller radius of curvature (FIG. 2);

a certain amount of axial traction may also be exerted on the enclosurel, resulting in that the latter is subjected to efforts tending tomaintain the same in closed position;

the object on which the traction is to be exerted may be subjected tothe action of an elastic return member tending to move the said objectback to its initial position when pressure is missing in the enclosure1.-

In the modified form of embodiment shown in FIG. 4, the cylindricalenclosure is traversed over its whole length by a pipe ll fed withpressurized fluid, for instance air, at both ends and penetrating intothe enclosure through dispensing holes 12 provided in the pipe wall.

Both ends of the enclosure are connected to the pipe ill by tively, theportion of the strap fixed to the thin walld may be two truncated wallsiii of supple inextensibie material,

preferably a polyamide woven material, secured by sticking to theenclosure itself or a to a rubber sleeve 14 forced onto the pipe. Thisenclosure, as shown in FIG. 1, is provided with a foldable wall formedof elements 15a, 15b, 15c... articulated according to folding generatinglies 17 of the enclosure.

These elements extend over the whole length of the enclosure and areinserted, for instance stuck, in the folds of the same height formed bythe corresponding elements 13a, 13b, 13c... of each truncated end wall13.

In addition to its function consisting in feeding the traction cylinderwith air, the conduit 11 also fulfills the function of a resistingmember preventing the end walls 13 of the enclosure from being expelledas a result of the pressure of the air contained in the enclosure.

In this modified form of embodiment, the unfolding and folding of thewall 15 are simple and better controlled than in the form ofconstruction shown in FIGS. 1 to 3, and this not only increases theefficiency of the traction cylinder, but also improves its reliabilityin operation.

In the modification illustrated in FIG. 5, only one traction member 18is used, the balancing along the line of action yy perpendicular to thedirection of the generatrix x'x of the enclosure 1 being obtained as aresult of the symmetrical arrangement of the portion 180 and theportions 18b, 180 of the member 18 on either side of the axis y'y;

It is to be understood that the invention should not at all be construedas beinglimited to the forms of embodiment shown and described, as thelatter have been given by way of example only. In particular, theinvention comprises all means constituting technical equivalents to themeans described as well as their combinations, should they be carriedout according to the spirit of the invention.

I claim:

1. A fluid-actuated traction cylinder for moving closer distant memberscomprising a substantially cylindrical tubular supple deformableenclosure closed at both ends and the lateral surface of which compriseselements articulated with one another along the generatrices of thesurface of said cylindrical enclosure, supple band means mounted on saidcylindrical surface and having its ends attached to said members andmeans for inflating or deflating said enclosure with a pressurizedfluid.

2. A fluid-actuated traction cylinder according to claim 1, wherein atleast some of the said articulated elements of the said supplecylindrical enclosure are inextensible.

3. A fluid-actuated traction cylinder according to claim 2, wherein saidband means is secured to one of the said inextensible elements of theenclosure.

4. A fluid-actuated traction cylinder according to claim 2, wherein whenthe said enclosure is in the deflated state, at

least some of the said elements are accordion-pleated.

5. A fluid-actuated traction cylinder for moving closer distant memberscomprising a substantially cylindrical tubular, supple deformableenclosure closed at both ends and whose lateral surface compriseselements articulated with one another along the generatrices of thesurface of said cylindrical enclosure, supple band means mounted on saidcylindrical surface and having its ends attached to said members andmeans for inflating or deflating said enclosure with a pressurizedfluid, at least some of the said articulated elements of said supplecylindrical enclosure being inextensible, said band means being securedtonne of the said inextensible elements of said enclosure, at least someof said elements being accordion pleated when said enclosure isdeflated, and wherein that one of the said inextensible elements towhich the said band means is secured has a section substantially in theshape of an are of a circle whose curvature varies according to theextent of inflation of the traction cylinder and which, in the deflatedstate of the enclosure, forms an almost closed circle in which saidaccordion-pleated elements of the enclosure are located.

6. A fluid-actuated traction cylinder according to claim 4, wherein thesaid accordion-pleated elements are constituted by a zigz ag-fol dedsheet provided alon the folding edges with longitudinal stiffeningelements of elas c material constituting members serving to return thesaid enclosure to its folded position.

7. A fluid-actuated traction cylinder for moving closer distant memberscomprising a substantially cylindrical tubular, supple deformableenclosure closed at both ends and whose lateral surface compriseselements articulated with one another along the generatrices of thesurface of said cylindrical enclosure, supple band means mounted on saidcylindrical surface and having its ends attached to said members andmeans for inflating or deflating said enclosure with a pressurizedfluid, the said inflating and deflating means comprising fluid inlet andescape openings opening in the enclosure and means comprising suppledeformable truncated portions connecting said conduits to the enclosure,the top of each of such truncated portions being connected to acorresponding conduit and the base of each of which truncate portions isconnected to the enclosure.

8. A fluid-actuated traction cylinder according to claim 7, wherein eachsaid truncated portion is integral with the enclosure.

9. A fluid-actuated traction cylinder according to claim 7, wherein eachsaid truncated portion consists of a separate member secured to theenclosure and is arranged within the latter with its narrowed portionturned towards the interior of the traction cylinder.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 570 814Dated March 16 1971 Inventor(s) Paul Zuppi ger It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

On the cover sheet insert [32] Claim priority application Switzerland,3001/68 Feb. 28, 1968 Signed and sealed this 17th day of August 1971(SEAL) Attest:

EDWARD M.FLETCHER, JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents FORM PC4050 (0-59) -oc 5037

1. A fluid-actuated traction cylinder for moving closer distant memberscomprising a substantially cylindrical tubular supple deformableenclosure closed at both ends and the lateral surface of which compriseselements articulated with one another along the generatrices of thesurface of said cylindrical enclosure, supple band means mounted on saidcylindrical surface and having its ends attached to said members andmeans for inflating or deflating said enclosure with a pressurizedfluid.
 2. A fluid-actuated traction cylinder according to claim 1,wherein at least some of the said articulated elements of the saidsupple cylindrical enclosure are inextensible.
 3. A fluid-actuatedtraction cylinder according to claim 2, wherein said band means issecured to one of the said inextensible elements of the enclosure.
 4. Afluid-actuated traction cylinder according to claim 2, wherein when thesaid enclosure is in the deflated state, at least some of the saidelements are accordion-pleated.
 5. A fluid-actuAted traction cylinderfor moving closer distant members comprising a substantially cylindricaltubular, supple deformable enclosure closed at both ends and whoselateral surface comprises elements articulated with one another alongthe generatrices of the surface of said cylindrical enclosure, suppleband means mounted on said cylindrical surface and having its endsattached to said members and means for inflating or deflating saidenclosure with a pressurized fluid, at least some of the saidarticulated elements of said supple cylindrical enclosure beinginextensible, said band means being secured to one of the saidinextensible elements of said enclosure, at least some of said elementsbeing accordion pleated when said enclosure is deflated, and whereinthat one of the said inextensible elements to which the said band meansis secured has a section substantially in the shape of an are of acircle whose curvature varies according to the extent of inflation ofthe traction cylinder and which, in the deflated state of the enclosure,forms an almost closed circle in which said accordion-pleated elementsof the enclosure are located.
 6. A fluid-actuated traction cylinderaccording to claim 4, wherein the said accordion-pleated elements areconstituted by a zigzag-folded sheet provided along the folding edgeswith longitudinal stiffening elements of elastic material constitutingmembers serving to return the said enclosure to its folded position. 7.A fluid-actuated traction cylinder for moving closer distant memberscomprising a substantially cylindrical tubular, supple deformableenclosure closed at both ends and whose lateral surface compriseselements articulated with one another along the generatrices of thesurface of said cylindrical enclosure, supple band means mounted on saidcylindrical surface and having its ends attached to said members andmeans for inflating or deflating said enclosure with a pressurizedfluid, the said inflating and deflating means comprising fluid inlet andescape openings opening in the enclosure and means comprising suppledeformable truncated portions connecting said conduits to the enclosure,the top of each of such truncated portions being connected to acorresponding conduit and the base of each of which truncate portions isconnected to the enclosure.
 8. A fluid-actuated traction cylinderaccording to claim 7, wherein each said truncated portion is integralwith the enclosure.
 9. A fluid-actuated traction cylinder according toclaim 7, wherein each said truncated portion consists of a separatemember secured to the enclosure and is arranged within the latter withits narrowed portion turned towards the interior of the tractioncylinder.